Dickensblum9935

IMPORTANCE Paramyxovirus genomes are contained within a noncovalent homopolymer of its nucleoprotein (NP) and form helical nucleocapsids (NC) whose 3' ends contain the promoters for the initiation of viral RNA synthesis. This work suggests that these NC 3' ends may play another role in the virus life cycle via their specific interaction with virus-modified cell membranes needed for the incorporation of viral NCs into budding virions.Most viruses undergo a maturation process from a weakly self-assembled, noninfectious particle to a stable, infectious virion. For herpesviruses, this maturation process resolves several conflicting requirements (i) assembly must be driven by weak, reversible interactions between viral particle subunits to reduce errors and minimize the energy of self-assembly, and (ii) the viral particle must be stable enough to withstand tens of atmospheres of DNA pressure resulting from its strong confinement in the capsid. With herpes simplex virus 1 (HSV-1) as a prototype of human herpesviruses, we demonstrated that this mechanical capsid maturation is mainly facilitated through capsid binding auxiliary protein UL25, orthologs of which are present in all herpesviruses. Through genetic manipulation of UL25 mutants of HSV-1 combined with the interrogation of capsid mechanics with atomic force microscopy nano-indentation, we suggested the mechanism of stepwise binding of distinct UL25 domains correlated with capsid maturation and DNA packaging. These findings demonstrate another paradigm of viruses as elegantly programmed nano-machines where an intimate relationship between mechanical and genetic information is preserved in UL25 architecture. IMPORTANCE The minor capsid protein UL25 plays a critical role in the mechanical maturation of the HSV-1 capsid during virus assembly and is required for stable DNA packaging. We modulated the UL25 capsid interactions by genetically deleting different UL25 regions and quantifying the effect on mechanical capsid stability using an atomic force microscopy (AFM) nanoindentation approach. This approach revealed how UL25 regions reinforced the herpesvirus capsid to stably package and retain pressurized DNA. Our data suggest a mechanism of stepwise binding of two main UL25 domains timed with DNA packaging.Human herpesvirus 6 (HHV-6) belongs to the betaherpesvirus subfamily and is divided into two distinct species, HHV-6A and HHV-6B. HHV-6 can infect nerve cells and is associated with a variety of nervous system diseases. Recently, the association of HHV-6A infection with Alzheimer's disease (AD) has been suggested. The main pathological phenomena of AD are the accumulation of β-amyloid (Aβ), neurofibrillary tangles, and neuroinflammation; however, the specific molecular mechanism of pathogenesis of AD is not completely clear. In this study, we focused on the effect of HHV-6A U4 gene function on Aβ expression. Coexpression of HHV-6A U4 with amyloid precursor protein (APP) resulted in inhibition of ubiquitin-mediated proteasomal degradation of APP. Consequently, accumulation of β-amyloid peptide (Aβ), insoluble neurofibrillary tangles, and loss of neural cells may occur. Immunoprecipitation coupled with mass spectrometry (IP-MS) showed that HHV-6A U4 protein interacts with E3 ubiquitin ligase composed of DDB1 annto the etiological hypothesis of HHV-6A in AD that can help further analyses.Ongoing health care-associated outbreaks of the multidrug-resistant yeast Candida auris have prompted the development of several rapid DNA-based molecular diagnostic tests. These tests do not distinguish between live and dead C. auris cells, limiting their use for environmental surveillance and containment efforts. We addressed this critical gap by developing a reverse transcription (RT)-quantitative real-time PCR (RT-qPCR) assay to rapidly detect live C. auris in health care environments. This assay targeted the internal transcribed spacer 2 (ITS2) ribosomal gene by obtaining pure RNA followed by reverse transcription (ITS2 cDNA) and qPCR. ITS2 cDNA was not detectable in bleach-killed cells but was detectable in heat- and ethanol-killed C. auris cells. The assay was highly sensitive, with a detection limit of 10 CFU per RT-qPCR. Validation studies yielded positive cycle threshold (CT) values from sponge matrix samples spiked with 102 to 105 CFU of live C. auris, while dead (bleach-killed) C. auris (105/mL) or other live Candida species (105/mL) had no CT values. Finally, 33 environmental samples positive for C. auris DNA but negative by culture were all negative by RT-qPCR assay, confirming the concordance between culture and the PCR assay. The RT-qPCR assay appears highly reproducible, robust, and specific for detecting live C. auris from environmental samples. The Candida auris RT-qPCR assay could be an invaluable tool in surveillance efforts to control the spread of live C. auris in health care environments.Aspergillus antibody testing is key for the clinical diagnosis of chronic pulmonary aspergillosis (CPA) with high sensitivity. However, false-negative results in patients with CPA might be obtained, depending on the Aspergillus species. The aim of this study was to investigate which factors are associated with false-negative results in Aspergillus precipitin tests and whether the sensitivity of precipitin tests in CPA is influenced by Aspergillus fumigatus and non-fumigatus Aspergillus species. Between February 2012 and December 2020, 116 consecutive antifungal treatment-naive patients with CPA were identified and included in this retrospective chart review. Aspergillus species isolated from the respiratory tract of patients were identified by DNA sequencing. Characteristics of patients with positive and negative results for Aspergillus precipitin tests were compared. The sensitivity of the Aspergillus precipitin tests was compared between patients with A. fumigatus-associated CPA and non-fumigatus Aspergillus-associated CPA. A non-fumigatus Aspergillus species was the only factor significantly associated with negative Aspergillus precipitin test results in patients with CPA in the multivariate analysis (hazard ratio, 8.3; 95% confidence interval, 3.2 to 22.1; P  less then  0.0001). The positivity of the Aspergillus precipitin test for patients with non-fumigatus Aspergillus-associated CPA was lower than that for patients with A. fumigatus-associated CPA (84.8% versus 37.9%; P  less then  0.0001). These results revealed that the presence of non-fumigatus Aspergillus-associated CPA should be considered with a negative Aspergillus precipitin test; this finding may prevent diagnostic delay or misdiagnosis for CPA.ASCO Rapid Recommendations Updates highlight revisions to select ASCO guideline recommendations as a response to the emergence of new and practice-changing data. The rapid updates are supported by an evidence review and follow the guideline development processes outlined in the ASCO Guideline Methodology Manual. The goal of these articles is to disseminate updated recommendations, in a timely manner, to better inform health practitioners and the public on the best available cancer care options.Iodinate anions are important in the chemistry of the atmosphere where they are implicated in ozone depletion and particle formation. The atmospheric chemistry of iodine is a complex overlay of neutral-neutral, ion-neutral, and photochemical processes, where many of the reactions and intermediates remain poorly characterized. This study targets the visible spectroscopy and photostability of the gas-phase hypoiodite anion (IO-), the initial product of the I- + O3 reaction, by mass spectrometry equipped with resonance-enhanced photodissociation and total ion-loss action spectroscopies. It is shown that IO- undergoes photodissociation to I- + O (3P) over 637-459 nm (15700-21800 cm-1) because of excitation to the bound first singlet excited state. Electron photodetachment competes with photodissociation above the electron detachment threshold of IO- at 521 nm (19200 cm-1) with peaks corresponding to resonant autodetachment involving the singlet excited state and the ground state of neutral IO possibly mediated by a dipole-bound state.Structural, electronic, and chemical nanoscale modifications of transition metal dichalcogenide monolayers alter their optical properties. A key missing element for complete control is a direct spatial correlation of optical response to nanoscale modifications due to the large gap in spatial resolution between optical spectroscopy and nanometer-resolved techniques. Here, we bridge this gap by obtaining nanometer-resolved optical properties using electron spectroscopy at cryogenic temperatures, specifically electron energy loss spectroscopy for absorption and cathodoluminescence for emission, which are then directly correlated to chemical and structural information. In an h-BN/WS2/h-BN heterostructure, we observe local modulation of the trion (X-) emission due to tens of nanometer wide dielectric patches. Trion emission also increases in regions where charge accumulation occurs, close to the carbon film supporting the heterostructures. The localized exciton emission (L) detected here is not correlated to strain above 1%, suggesting point defects might be involved in their formation.The mechanism and origin of ligand effects on stereoinversion of Pd-catalyzed synthesis of tetrasubstituted olefins were investigated using DFT calculations and the approach of energy decomposition analysis (EDA). The results reveal that the stereoselectivity-determining steps are different when employing different phosphine ligands. This is mainly due to the steric properties of ligands. With the bulkier Xantphos ligand, the syn/anti-to-Pd 1,2-migrations determine the stereoselectivity. While using the less hindered P(o-tol)3 ligand, the 1,3-migration is the stereoselectivity-determining step. The EDA results demonstrate that Pauli repulsion and polarization are the dominant factors for controlling the stereochemistry in 1,2- and 1,3-migrations, respectively. The origins of differences of Pauli repulsion and polarization between the two stereoselective transition states are further identified.Herein, we report the development of a transition-metal-free oxidative C(sp2)-C(sp2) coupling of readily available boronic acids and organolithiums via phenothiazinium ions. Various biaryl, styrene, and diene derivatives were obtained using this reaction system. selleck products The key to this process is N-methylphenothiazine S-oxide (PTZSO), which allows efficient conversion of boronic acids to phenothiazinium ions. The mechanism of phenothiazinium formation using PTZSO was investigated using theoretical calculations and experiments, which provided insight into the unique reactivity of PTZSO.Recently, one has been observing abundant studies on the application of surface acoustic waves (SAWs) in solid substrates for manipulating liquids and particulates in micron-to-nanometer thick films and channels and in porous media. At these length scales, contributions of SAWs to the electrical double layer (EDL) of ions and of the latter to particulates and flow may become appreciable. However, the nature of the interplay between SAWs and EDLs is unknown. We demonstrate the contribution of a SAW to the near-equilibrium electrical and ion-concentration fields in an EDL near inert and piezoelectric substrates. In particular, we concentrate on the leakage of transient and steady components of electrical potential through the excited EDL. Far from the solid, the leakage may be interpreted by different models of the EDL to give information about the EDL characteristic relaxation time, ζ-potential, and the Stern layer therein. In addition, the analysis given here may explain observed SAW-induced electrochemical effects on piezoelectric substrates.